In brief: A recent cross-sectional study (KM Clark et al. J Pediatr 2017; 181: 56-61) showed that breastfeeding at 9 months of age in Chinese infants was associated with iron deficiency anemia..  Iron deficiency can contribute to neurodevelopmental delays in addition to anemia.

• In Zhejiang (n=142), 27.5% of breastfed infants had iron deficiency anemia (IDA) compared with 0% of formula-fed infants.
• In Hebei (n=813) , 44% of breastfed infants had IDA compared with 2.8% of formula-fed infants.

My take: In later infancy (after 6 months of age), breastfeeding infants are at increased risk for iron deficiency anemia.